A student uses a prism spectrometer to analyze three bright spectral lines emitted by…
PHYSICS · Multi-part · CBSE · Physics · The Human Eye and the Colourful World · The Human Eye and the Colourful World
Problem
A student uses a prism spectrometer to analyze three bright spectral lines emitted by an unknown gas. The instrument directly provides the wavelengths of the lines as 470nm, 530nm, and 650nm.
(a) For each measured wavelength, state the approximate perceived color of the line.
(b) Rank the three spectral lines by increasing frequency.
(c) The student notices that refraction causes different angular deviations for the three lines inside the prism. Without performing calculations, predict which of the three lines undergoes the greatest angular deviation and justify your prediction.
(d) Sketch a qualitative graph of light speed inside the prism material versus wavelength for the range spanned by the three lines, and clearly mark the positions of the three wavelengths identified in part (a).